It is known that a high proportion of the population, estimated by the dental profession to be in the region of 20 to 25% of the total population, suffers from hypersensitivity or hyperaesthesia of the teeth, in other words pain in response to mechanical, chemical and thermal stimuli, without any visible dental diseases such as caries which would require dental treatment.
The hypersensitivity of the teeth occurs mainly at the neck of the teeth when the soft dentine becomes exposed between the boundary of the enamel and the gum line due to recession of the gums. The action of lactic acid forming lactobacilli or the mechanical action of braces (even in children) or the engaging parts of dentures during chewing may also damage the protective enamel so that the dentinal canaliculi which are then exposed transmit every mechanical, chemical or thermal irritation as a painful stimulus to the tooth pulp.